多介质环境目标值的应用

本文概述了多介质目标德的SAM/Ⅰ的方法。多介质目标值包括环境目标值和排放目标值。点源分析包括SAM/ⅠA,SAM/ⅠB,SAM/Ⅰ,SAM/Ⅱ。在缺少环境质量标准的情况下,使用多介质环境目标值有较强的适用性,且具有省时、省力、经济等特点。本文将多介质目标值的SAM/ⅠA点源分析方法引入聚氯乙烯生产废水的环境评价中,取得较为满意的结果。     

金属体积成形过程有限元模拟中六面体网格重划技术的研究

针对金属体积成形过程有限元模拟中的网格重划问题 ,提出了基于边界构形的有限元网格重划技术 ,并对其中的一系列技术处理进行了详尽的讨论。将该技术应用于矩形块体镦粗过程的有限元模拟中 ,较好地解决了六面体网格重划问题。     

建立绿色包装系统的可行性研究报告

笔者从我国包装的现状分析入手，探讨建立绿色包装系统的可行性和必要性，提出建立绿色包装系统的具体措施和实施方案。     

凡口铅锌矿床地球化学特征及成矿作用分析

凡口铅锌矿床是发育于碳酸盐岩建造中的海底热泉喷溢沉积矿床,以“一大二富三集中”的特点和典型的地质地球化学特征吸引着中外矿床地质工作者。常量元素和矿化元素的分布、矿物包裹体特征、稀土元素组成和硫同位素组成反映出该矿床与外生作用有关。铅同位素组成具有壳源和下地壳来源铅的特征,矿物包裹体水氢、氧同位素组成表明,成矿溶液可能与深层建造水有关,后期与大气降水有关。矿区主要矿层经历海底热泉喷溢沉积-成岩的演化。     

高校要加强大学生礼仪教育

本文列举了大学生在学校多种场合和情景中礼仪素养缺失的种种表现,并多方面分析问题产生的原因,最后简要提出了高校要加强大学生礼仪教育的对策。     

飞机喷洒农药的损失分析

通过田间试验，对装配ＧＰ－８１扁扇型喷头的运５飞机在水稻和棉花上喷洒农药中的药液损失进行了分析，同时讨论了２，４－Ｄ丁酯对敏感作物的影响。结果表明，一元三次方程Ｙ＝ｂ０＋ｂ１ｘ２＋ｂ２ｘ＾２＋ｂ３ｘ＾３能很好地描述药液飘移与下风距离的关系，方程中的参数具有明确的实验意义；２，４－Ｄ丁酰对７００ｍ下风距离内的向日葵类高敏感植物有明显药害，对３５０ｍ范围内的大豆等中等敏感植物也有药害；药液由于飘移和蒸     

废醋酸锌催化剂回收醋酸锌工艺研究

对从废醋酸锌催化剂中浸取醋酸锌进行了实验研究,考察了废催化剂颗粒大小,浸取剂种类和用量、温度和浸取时间等因素对醋酸锌浸取率的影响。     

云南小水泥粉尘污染及治理探讨

进入九十年代后，由于盲目上马，布局失控，云南省小水泥迅速发展。落后的工艺技术和管理使水泥粉尘排放量剧增，对大气造成了严重污染。应积极推进小水泥结构调整，加强管理，综合治理，才能减少粉尘排放量，改善大气环境质量     

Detecting neural tube defects by amniocentesis between 11 and 15 weeks' gestation

Forty-two open neural tube defects (NTDs) were identified in our series of 7440 amniocenteses tested between 11 and 15 weeks of gestation. Using a cut-off of ≥2.0 MOM, the detection rate for open NTDs was 95 per cent; 100 per cent each for anencephaly and spina bifida; and 78 per cent for encephalocele. Two encephaloceles had AFP levels less than 2.0 MOM and negative AChEs. Thirty-four (81 per cent) of these NTDs were tested between 13 and 15 weeks and 8 (19 per cent) before 13 weeks. There were 0.6 per cent false positives by AFP (excluding serious abnormalities and fetal death) and 0.1 per cent after AChE. The likelihood of an open NTD after an elevated AFP (≥2.0 MOM) was 24 and 77 per cent for any serious abnormality. These results, when combined with an earlier study, indicate that amniotic fluid AFP appears to be as sensitive a test for open NTDs between 13 and 15 weeks as between 16 and 20 weeks. Additional experience is necessary to determine this before 13 weeks.     

Prenatal diagnosis of herlitz junctional epidermolysis bullosa by amniocentesis

Herlitz junctional epidermolysis bullosa (HJEB) is a severe blistering disorder which usually results in death during infancy. We have previously shown that the anchoring filament protein laminin-5 (kalinin/nicein), which mediates keratinocyte attachment and dermal–epidermal cohesion, is abnormally expressed in individuals with HJEB. Laminin-5 was detected by Western blot analysis in amniotic fluid from 44 consecutive normal secondtrimester control pregnancies, but was undetectable in second-trimester amniotic fluid from four pregnancies with fetuses affected by HJEB. In one case of severe non-Herlitz JEB, laminin-5 was detected in both amniotic fluid and skin. In human amniotic fluid, the laminin-5 a3 subunit was processed to a major 165 kD species and a minor 145 kD species and the β2 subunit was partially processed to 105 kD. Although laminin-5 was covalently associated with laminin-6 (K-laminin) in amniotic membrane, no covalent interaction was detected in amniotic fluid. Laminin-5 from amniotic fluid strongly supported keratinocyte attachment. These results suggest that Western blot analysis of second-trimester amniotic fluid is useful in determining the prenatal diagnosis of HJEB and that laminin-5 may serve a physiologically important function in amniotic fluid.